Application of Topological Sensitivity Toward Soft-Tissue Characterization From Vibroacoustography Measurements

2013 ◽  
Vol 8 (3) ◽  
Author(s):  
Huina Yuan ◽  
Bojan B. Guzina ◽  
Shigao Chen ◽  
Randall Kinnick ◽  
Mostafa Fatemi
Keyword(s):  
Tissue Characterization ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Imaging Method ◽  
Topological Sensitivity ◽  
Vibration Data ◽  
Viscoelastic Parameters ◽  
Resolution Imaging ◽  
Lesion Characterization

This study concerns the development and preliminary experimental verification of a topological sensitivity–based platform for the material characterization of tissue anomalies exposed by vibroacoustography-type imaging techniques. Vibroacoustography (VA) is a high-resolution imaging method that has been applied to the detection of pathological changes in soft tissues. Although the data provided by this method is related to the mechanical properties of tissue, the viscoelastic parameters of the object cannot be estimated by this imaging method itself. Topological sensitivity (TS) method is a data processing methodology that can be used to estimate the viscoelastic parameters of an object from vibration data. In this study, the concept of topological sensitivity is applied to interpret the vibroacoustography measurements for the purpose of lesion characterization. In the proposed approach, the topological sensitivity function, which signifies the variation of a given cost functional when an infinitesimal inclusion with trial material parameters is placed at the location of a point force, is formulated in terms of the adjoint field. The effectiveness of the resulting formula as a material indicator for lesion characterization is demonstrated by estimating the relative elastic parameters of a well-controlled neoprene sphere embedded in a tissue-mimicking phantom specimen.

Thumb Injuries and Instabilities. Part 2: Spectrum of Lesions

2021 ◽  
Vol 25 (02) ◽  
pp. 355-365
Author(s):  
Alain G. Blum ◽  
Marnix T. van Holsbeeck ◽  
Stefano Bianchi
Keyword(s):  
Soft Tissues ◽  
Imaging Techniques ◽  
Metacarpophalangeal Joint ◽  
Resonance Imaging ◽  
Ligament Injuries ◽  
First Line ◽  
Collateral Ligament ◽  
Traumatic Injuries ◽  
Line Imaging

AbstractThe motor function of the thumb and its alignment with regard to the hand make it particularly vulnerable to trauma. Pathology encountered in this joint is varied, and imaging techniques play a crucial role in the diagnosis and characterization of injury. Despite advances in imaging technology, acute thumb injuries remain a challenge for radiologists. Currently, standard radiography and ultrasonography are frequently used first-line imaging techniques. Computed tomography is most often indicated for complex fractures and dislocations. Magnetic resonance imaging may be used to optimally characterize soft tissues and bone marrow. In this article, we cover the most common traumatic injuries: fractures, dislocations, collateral ligament injuries of the metacarpophalangeal joint, as well as soft tissue lesions.

A NEW PARAMETER ESTIMATION METHOD FOR ONLINE SOFT TISSUE CHARACTERIZATION

2016 ◽  
Vol 16 (08) ◽  
pp. 1640019 ◽  
Author(s):  
JAEHYUN SHIN ◽  
YONGMIN ZHONG ◽  
JULIAN SMITH ◽  
CHENGFAN GU
Keyword(s):  
Soft Tissue ◽  
Linear Regression ◽  
Tissue Characterization ◽  
Soft Tissues ◽  
Unscented Kalman Filter ◽  
Estimation Method ◽  
Regression Method ◽  
Linear Regression Method ◽  
Non Linear

Dynamic soft tissue characterization is of importance to robotic-assisted minimally invasive surgery. The traditional linear regression method is unsuited to handle the non-linear Hunt–Crossley (HC) model and its linearization process involves a linearization error. This paper presents a new non-linear estimation method for dynamic characterization of mechanical properties of soft tissues. In order to deal with non-linear and dynamic conditions involved in soft tissue characterization, this method improves the non-linearity and dynamics of the HC model by treating parameter [Formula: see text] as independent variable. Based on this, an unscented Kalman filter is developed for online estimation of soft tissue parameters. Simulations and comparison analysis demonstrate that the proposed method is able to estimate mechanical parameters for both homogeneous tissues and heterogeneous and multi-layer tissues, and the achieved performance is much better than that of the linear regression method.

scholarly journals The value of Contrast-Enhanced Ultrasound in the characterization of vascular pattern of solid pancreatic lesions

2015 ◽  
Vol 17 (1) ◽  
pp. 16 ◽  
Author(s):  
Melania Ardelean ◽  
Roxana Sirli ◽  
Ioan Sporea ◽  
Simona Bota ◽  
Mirela Danila ◽  
...  
Keyword(s):  
Gold Standard ◽  
Imaging Techniques ◽  
Late Phase ◽  
Reference Method ◽  
Pancreatic Tumors ◽  
Imaging Method ◽  
Contrast Imaging ◽  
Cross Sectional ◽  
Solid Lesions

The aim of our study was to evaluate the accuracy of CEUS in the characterization of pancreatic solid lesions, considering cross sectional imaging techniques (CE-CT/MRI) as the “gold standard” methods. Material and methods: We performed a retrospective, monocentric study that included 91 solid pancreatic lesions which were evaluated by CEUS and by a second- line contrast imaging technique (CT or MRI), considered as the reference method. Results: The rate of a conclusive diagnosis based on a typical enhancement pattern was 94% (78/83 cases). In 72 cases out of 83 (86.7%) there was a perfect concordance between CEUS and the “gold-standard” imaging method (CE-CT/MRI). In our study, 88% (73/83) of the pancreatic lesions were categorized as malignant due to their typical wash-out aspect in the late phase. The overall accuracy of CEUS for the differential diagnosis of solid pancreatic tumors was approximately 81%. The accuracy of CEUS for the diagnosis of hypoen- hancing pancreatic tumors was approximately 89.1%; while for the diagnosis of hyperenhancing pancreatic tumors it was ap- proximately 72.8%. Conclusion: CEUS allows the differentiation between hypo- vs. hyperenhancing pancreatic solid lesions, with a considerable diagnostic accuracy, a fundamental step in the precise diagnosis of pancreatic tumors.

A Coupled Tube-Tissue Model for Frequency Calculation of Arterial Tubes With Tissue

2003 ◽  
Author(s):  
Xiaoming Zhang ◽  
Mostafa Fatemi ◽  
James F. Greenleaf
Keyword(s):  
Vibration Analysis ◽  
Tissue Characterization ◽  
Experimental Studies ◽  
Radiation Force ◽  
Imaging Method ◽  
Large Artery ◽  
Rubber Tube ◽  
Tissue Model ◽  
Frequency Calculation

Vibro-acoustography is a new noncontact imaging method based on the radiation force of ultrasound. We extend this new technique for tissue characterization of arterial vessels by vibration techniques. In this paper a theoretical model for vibration analysis of arterial vessel with tissue is developed. Experimental studies were carried out on a silicone rubber tube embedded in a cylindrical gelatin phantom of larger radius, which simulates a large artery and the tissue body. The fundamental mode is well excited by the radiation force of ultrasound. The fundamental frequency was measured 81.8 Hz for a tube-phantom structure that is quite close to our theoretical prediction of 83.3 Hz.

Observation of grain boundary segregation in advanced ceramics using high-resolution imaging SIMS

1995 ◽  
Vol 53 ◽  
pp. 324-325
Author(s):  
R. Levi-Setti ◽  
K. K. Soni ◽  
J. M. Chabala ◽  
A. M. Thompson
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
High Spatial Resolution ◽  
Imaging Techniques ◽  
Boundary Segregation ◽  
Ion Microprobe ◽  
Broad Beam ◽  
Resolution Imaging ◽  
Boundary Chemistry

The significance of grain boundaries in controlling processing and properties of ceramics is widely acknowledged. Through the addition of suitable dopants to ceramics, their processability and properties can be improved. These dopants may segregate to grain boundaries, but the characterization of boundary chemistry is a challenging task. Studies of segregation phenomena require the application of high-lateralresolution techniques such as STEM/AEM or surface sensitive techniques such as AES, XPS. These techniques require rigorous sample preparation and have their limitations.The scanning ion microprobe is a powerful tool that has exhibited unprecedented potential in the characterization of grain boundaries in ceramics. When interfaced to a mass spectrometer (magnetic sector in our case), this instrument allows mapping of many trace elements at nanometer level in bulk specimens. The combination of excellent sensitivity and high spatial resolution enables direct imaging of grain boundary segregants. The results thus obtained are free from artifacts that typically complicate analysis with broad beam, non-imaging techniques.

Image-Based Simulation for the Mechanical Characterization of Scaffolds

2009 ◽  
Author(s):  
Bruno Notarberardino ◽  
Philippe G. Young ◽  
Liang Hao ◽  
David R. Raymont ◽  
Irene G. Turner ◽  
...  
Keyword(s):  
Mechanical Characterization ◽  
Imaging Techniques ◽  
Sensitivity Analyses ◽  
High Resolution Imaging ◽  
Porous Structures ◽  
Micro Ct ◽  
Bulk Properties ◽  
Resolution Imaging ◽  
Scan Data

Recent development of high resolution imaging modalities such as Micro-CT allow realistic porous structures to be straightforwardly and accurately scanned with sub-micron image resolutions possible on some commercially available systems. Combined with novel meshing techniques, these imaging techniques allow for robust and rapid conversion of the 3D scan data into finite element and finite volume meshes which can straightforwardly be used to characterize the response [1]. In addition, various image processing tools allow for interesting sensitivity analyses to be carried out helping to elucidate relationships between key architectural parameters, such as rib thickness, and bulk properties. A number of studies will be shown which demonstrate the ease with which fidelic models of the complex micro-architectures of bio-scaffolds can be generated.

scholarly journals Clinical applications of imaging modalities of the carpal joint in dogs with particular reference to the carpal canal

2020 ◽  
Vol 64 (1) ◽  
pp. 169-174
Author(s):  
Angelika Tobolska ◽  
Zbigniew Adamiak ◽  
Joanna Głodek
Keyword(s):  
Diagnostic Imaging ◽  
Soft Tissues ◽  
Current Knowledge ◽  
Wrist Joint ◽  
Imaging Techniques ◽  
Imaging Modalities ◽  
Imaging Method ◽  
Joint Surfaces ◽  
Small Joint ◽  
Carpal Joint

AbstractThe structure of the canine carpal joint is complex. This small joint consists of articulations that include the antebrachiocarpal, middle, carpometacarpal, and intercarpal joint surfaces. A large number of ligaments and tendons support and stabilise the carpus in dogs. Many injuries of this joint in dogs are not correctly recognised, diagnosed, or treated due to the limited use of diagnostic imaging methods. Radiography, the most common of them, has extensive application in diagnosing the causes of lameness in small animals. Other techniques, such as ultrasonography, computed tomography, and magnetic resonance imaging visualise other joint structures and surrounding soft tissues. However, these imaging modalities are rarely used to diagnose diseases and injuries of the canine carpus at present. The main reason for this is the small amount of research carried out and the lack of a properly described methodology for the use of imaging techniques. The wide use of all diagnostic imaging tools in the diagnosis of diseases and injuries of the wrist joint in humans shows that conducting studies on dogs could expand current knowledge. The use of these techniques in veterinary medicine could facilitate diagnosis and subsequent therapy of carpal disorders in dogs. MRI is the most frequently used imaging method in human medicine for visualisation of abnormalities of joints. This method could become a valuable part of the detection of inflammatory, traumatic, and degenerative diseases of the carpal joint in dogs.

Image-Based Simulation for the Mechanical Characterization of Scaffolds

2010 ◽  
Author(s):  
Bruno Notarberardino ◽  
Philippe G. Young ◽  
Liang Hao ◽  
David R. Raymont ◽  
Irene G. Turner ◽  
...  
Keyword(s):  
Mechanical Characterization ◽  
Imaging Techniques ◽  
Sensitivity Analyses ◽  
High Resolution Imaging ◽  
Porous Structures ◽  
Micro Ct ◽  
Bulk Properties ◽  
Resolution Imaging ◽  
Scan Data

Recent development of high resolution imaging modalities such as Micro-CT allow realistic porous structures to be straightforwardly and accurately scanned with sub-micron image resolutions possible on some commercially available systems. Combined with novel meshing techniques, these imaging techniques allow for robust and rapid conversion of the 3D scan data into finite element and finite volume meshes which can straightforwardly be used to characterize the response [1]. In addition, various image processing tools allow for interesting sensitivity analyses to be carried out helping to elucidate relationships between key architectural parameters, such as rib thickness, and bulk properties. A number of studies will be shown which demonstrate the ease with which fidelic models of the complex micro-architectures of bio-scaffolds can be generated.

SEM/FESEM imaging of lamellar structures in melt extruded polyethylene films

1992 ◽  
Vol 50 (2) ◽  
pp. 1142-1143
Author(s):  
R.T. Chen ◽  
M.G. Jamieson ◽  
R. Callahan
Keyword(s):  
Imaging Techniques ◽  
Membrane Surface ◽  
High Stress ◽  
Extrusion Direction ◽  
Polymeric Membranes ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Crystalline Polymers ◽  
Lamellar Structures ◽  
Resolution Imaging

“Row lamellar” structures have previously been observed when highly crystalline polymers are melt-extruded and recrystallized under high stress. With annealing to perfect the stacked lamellar superstructure and subsequent stretching in the machine (extrusion) direction, slit-like micropores form between the stacked lamellae. This process has been adopted to produce polymeric membranes on a commercial scale with controlled microporous structures. In order to produce the desired pore morphology, row lamellar structures must be established in the membrane precursors, i.e., as-extruded and annealed polymer films or hollow fibers. Due to the lack of pronounced surface topography, the lamellar structures have typically been investigated by replica-TEM, an indirect and time consuming procedure. Recently, with the availability of high resolution imaging techniques such as scanning tunneling microscopy (STM) and field emission scanning electron microscopy (FESEM), the microporous structures on the membrane surface as well as lamellar structures in the precursors can be directly examined.The materials investigated are Celgard® polyethylene (PE) flat sheet membranes and their film precursors, both as-extruded and annealed, made at different extrusion rates (E.R.).

Sign in / Sign up

Export Citation Format

Share Document